Tentering apparatus for application of controlled, uniform tension to fabrics



May 14, 1968 c. HARMON ETAL TENTERING APPARATUS FOR APPLICATION OF CONTROLLED, UNIFORM TENSION TO FABRICS 2 Sheets-Sheet 1 Filed April 12, 1966 INVENTORS:

flAwMo/v S M/7 ATTORNEY- May 14, 1968 c. HARMON ETAL 3,382,554

TENTERING APPARATUS FOR APPLICATION OF CONTROLLED, UNIFORM TENSION TO FABRICS Filed April 12, 1966 Z Sheets-Sheet 2 INVENTORS: 6:41P; r4 E A IPA/01V c/o/v/v u. M/Tf/ TTORNEY.

United States Patent 3,382,554 TENTERING APPARATUS FOR APPLICATION OF CONTROLLED, UNIFORM TENSION T0 FABRICS Carlyle Harmon, Scotch Plains, and John J. Smith, New

Brunswick, N.J., assignors to Johnson & Johnson, a

corporation of New Jersey Filed Apr. 12, 1966, Ser. No. 542,022 5 Claims. (CI. 26-57) ABSTRACT OF THE DISCLOSURE An improvement in tentering machines of the type which have a pair of claims which grip the selvages of the fabric and spread the fabric to its full width. The chains are mounted on a track and the positioning between the chains is controlled by a plurality of screw means. The improvement comprises splitting the track into an upper and lower portion along its entire length and controlling the position of the lower portion by these screw means while separately controlling the position of the upper portion with separate control means to apply uniform and desired tension along the entire length of the path of the chains.

This invention relates to apparatus for applying tension to materials, and more particularly, to apparatus for applying a controlled tension and, if desired, a measured tension across the width of a fabric while the fabric is undergoing other textile processing treatments.

In various standard processing steps in the treatment of textile fabrics, the fabric is passed through what is known as a tenter frame. This step is used generally to open a fabric to its full width and in some instances to stretch the fabric back to its original width or to a greater width after it has been given some type of treatment. Generally this step comprises gripping the selvage edges of the fabric and conveying these away from each other while the fabric is being conveyed forward in order to open the fabric to its full width. In some instances the fabric is dried or partially dried while being conveyed by the tenter frame. Similar tenter frames are also used in the processing of other materials, such as the orientation of plastic films.

In the prior art apparatus there have been various techniques and mechanisms for grasping the selvages which provide for automatically adjustable gripping means which may be varied over some distance in order to initially grasp selvages at varying widths. In these machines once the selvages are grasped, the amount of tension or stretch applied to the fabric .is not known and cannot be measured. The gripping means are attached to conveyors and these conveyors move in a fixed path so that the fabric is spread in the direction of its width as it is being conveyed by the tentering frame.

Before the fabric is placed on the tenter frame or while it is on the frame, it may be given one or more of various known textile treatments, such as mercerization, heat setting, resin treatment, washing, drying, etc. Hence, the tension applied to the fabric as it passes along the tenter frame may vary over wide limits depending on the relative direction of movement of the chains of the frame as well as the inherent action of the fabric, -i.e. whether it is relaxing or shrinking as it passes through the tenter frame. In all prior apparatus the amount of tension bein g applied to the fabric is not known, uncontrollable cannot be measured.

It has been discovered that by applying certain controlled tensions, generally close to the breaking point of the fabric for measurable periods of time, at various stages in the treatment of the fabric, some properties, such as tensile and tear strengths, may be improved in the fabric when subsequently treated with conventional textile resins or wash-wear treatments; however, in most prior art machines there is little if any ability to apply uniform controlled tension during the treatment of the fabric in order to obtain optimum benefits. Furthermore, in many present uses of tenter frames for processing various types of fabrics, films, etc., it would be helpful to the control of the processing and the automation of the process to both control and measure the tension applied during the process.

In accordance with the present invention, we have developed a tentering machine which comprises a pair of chains movable in adjacent paths. The chains are mounted on tracks and these tracks are fastened to screw means, which are adjustable, and control the general distance between the pair of chains. A track is split into an upper portion and a lower portion which are movable with respect to each other. The lower portion of this track is controlled by the screw means, and the upper portion is separately controlled to apply controlled and measured tension to material along the line of the path of the adjacent chain conveyors. The upper portion is mounted on rollers from the lower portion, and is preferably hydraulically controlled so that if excess tension is being applied to the material, this upper portion will roll towards the opposite chain, whereas if the material is being relaxed, the upper portion will .roll away from the opposite chain to increase the tension being applied to the material.

The invention will be more fully described when taken in conjunction with the accompanying drawings, wherein:

FIGURE 1 is a view in perspective of a machine in accordance with the present invention;

FIGURE 2 is an enlarged cross-sectional view taken along the line 2-2 of FIGURE 1; and

FIGURE 3 is an enlarged cross-sectional view taken along line 33 of FIGURE 1.

Referring to the drawings, in FIGURE 1 there is shown a tentering frame 10 which embodies the present invention. The tentering frame generally comprises a series of suitable upright supports 11. These supports are positioned along the length of the frame along each outside edge thereof. A support on one side of the frame is connected to the support directly opposite it by means of a cross brace 12. Slidably mounted on each cross brace are a pair of support tracks 13, one support track being mounted at one end of the cross brace and the other supand port track at the opposite end. Extending along the outside edges of the frame between support tracks on adjacent cross braces are frame sections 14. A frame section is pivotally connected to an adjacent frame section by means of a pin 15 which extends through the extended portion 16 of one section and the overlapping portion 17 of the adjacent section. The length of the frame may be modified by adding or subtracting the desired number of sections.

Mounted along each outside edge of the tentering frame are endless chains 18 and 19. Mounted from each chain are a series of clips 20 which ride in alined grooves extending the length of the frame sections at the outside edge-s thereof. Though clips are shown, pin-s or other suit able means for holding the edges of the fabric may also be used. The chains pass around the front sprockets 21 wherein they pick up the fabric. There are a number of various mechanisms presently used for varying this initial width in order to pick up the various width fabrics. The chains pass down the tentering frame holding the fabric between the two chains by means of the clips. On reaching the far sprockets 22 the clips are released and return to the front end of the frame while the fabric is carried on for various subsequent processing.

The distance between chains is controlled by means of screw mechanism 23 which moves opposed support tracks 13 either towards each other or away from each other. There is such a screw mechanism for each opposite pair of support tracks. The screw mechanisms are ac'tuated by the motor 24. The types of fabric which pass through a tentering frame are being treated or have been treated in some manner, such as by a heat setting operation, a starch treatment, resin treatments, a mercerizing treatment or similar finishing steps. .The fabrics are spread by the tentering frame and very often dried while under the tension to impart a smooth surface, remove wrinkles and so on. As previously discussed, it has been found that by controlling the tension applied to the fabric during various of these finishing operations, resin-treated fabrics which normally lose considerable strength due to the resin treatment will not lose as much strength if finished under a controlled tension.

Normally, depending upon the finishes applied to the fabric, the fabric may relax and tension decrease as it is being passed through the tentering frame or it may shrink and tension increase while being; passed through the tentering frame. Hence, in tentering operations due to the ever-changing characteristics of the fabrics as they pass through a tentering frame, it is virtually impossible to control the tension applied to the fabric. In the prior art tentering frames, it is also impossible to measure the tension applied to the fabric. It has now been discovered that by adding to the screw control of a tentering frame a hydraulic or similar control which is activated by the amount of tension applied to the fabric, we are able to control and measure the amount of tension applied during the tentering operation.

As more clearly shown in FIGURES 2 and 3, the support track is divided into a lower portion 33 and'an upper portion 34. The lower portion comprises the slidable bar piece 35 grooved at 31 to ride on cross brace 32. Through the her piece is a hole 36 to accommodate the screw 37. Attached to the bar piece in line with the hole is a. tube 37' at the end of which is a plate 38 and a threaded nut 39 welded to the plate. The nut engages the screw so that when the screw is turned the entire lower portion moves in or out. Movably mounted on this lower portion is the upper portion 34 comprising a cross piece 40 and two side pieces 41 and 42. Fastened to the side pieces by suitable screws 43 and bolts 44 are four rollers 4-5, which ride along the lower portion. Also mounted from the cross-piece and riding in a groove along the uppermost portion of this lower track are a pair of rollers 46. These rollers 4-5 and 46 control the movement of the upper portion to the lower portion. Riding in a groove in the cross-piece 40 is a pivot pin 51 holding two frame sections 52 and 53 pivotally together. The frames rest on the cross-piece. The groove and pin allow for expansion and contraction along the length of the frame depending on the processing accomplished by the frame. Riding in the grooves 55 in the frame sections are the clips 56 attached to the endless chain 57.

Attached from a suitable plate 60 from the upper portion is a hydraulic cylinder 61 mounted in suitable brackets 62 between the plate 60 and the plate 38 attached to the lower portion. The piston 63 in the hydraulic cylinder is actuated either by the fabric tension or by hydraulic pressure from a source not shown for the sake of clarity. To increase the tension on the fabric, the piston in the hydraulic cylinder moves to the right as shown in FIGURE 2 by increasing the hydraulic pressure through tube 64, thus moving the upper portion of the support track along the lower portion of the support track to increase the width between the diverging chains. If too much tension is being placed on the fabric, the pressure behind the piston tries to increase; however, it is automatically kept constant and allows the piston to move to the left displacing hydraulic fluid to maintain a constant pressure, moving the chains together until the upper portion reaches equilibrium at the desired tension.

Depending upon the number of sections used in the tentering frame and depending upon the type of fabric being processed and the type of finish to which this fabric has been subjected, various chains and various sections may be either parallel, diverge or converge or any combination of these in order to maintain the desired tension throughout the tenter frame.

Though a hydraulic control system has been described, it is to be appreciated that other suitable control systems may also be used, such as pneumatic, electrically actuated or other suitable means.

-In the tenter frame described, the gross adjustment, that is, the major setting between chains, is controlled by the lower portion of the track which is set by adjusting the screw on each section of the tentering frame. The dinal control, that is, the exact tension placed on the fabric as it passes through the tenter frame is controlled by the hydraulic means controlling the upper portion of the frame which is movable with respect to the lower portion, and is again independently controlled on each section of the tenter frame.

In operation the gross adjustment is set by means of the motor on the screw mechanism. The hydraulic mean are then set to apply the desired tension to the fabric. As the fabric passes through the tenter frame and relaxes or shrinks, as the case may be, the hydraulic means automatically adjust to apply the desired tension to the fabric during its entire pass through the frame.

Although no motors, pulleys, belts, gears or the like mechanical means have been completely illustrated or described in the specification for driving the various chain belts, actuating the clips, etc., it is to be appreciated that such elements have been omitted to keep the drawings and the description succinct and to avoid the introduction of matter which are well-known eXpcd-ients in the art. The mechanical driving means which are used are conventional and merely involve the application of well-known mechanical principles.

What is claimed is:

'1. In a tentering machine, said machine having a pair of chains with gripping means attached to said chains, said chains being movable in adjacent paths and said chains being mounted on a track wherein said track is fastened to a plurality of screw means positioned along the entire length of said track for controlling the distance between the pair of chains, the improvement which comprises: splitting each said track into an upper and lower portion, movable with respect to each other along the entire length of said track; controlling the position of said lower portion by said screw means and separately controlling the position of said upper portion with respect to said lower portion with a plurality of separate control means positioned along the entire length of said track whereby a desired and uniform tension may be applied to a material along substantially the entire length of the path of said adjacent pair of chains.

2. A tentering machine according to claim 1 said gripping means are clips.

3. A tentering machine according to claim 1 wherein wherein 5 d the sep'arate control means controlling the upper portion References Cited hydrauhc f UNITED STATES PATENTS 4. A tenterlng machme according to clalm 1 wherein the upper portion is mounted on rollers contacting the 1746473 2/1930 H'Oey 26 52 lower portion 5 3,150,432 9/1904 McCreary 26-57 5. A tentering machine according to claim 1 wherein FOREIGN PATENTS the gripping means are mounted on said chains, the 4 03 2 193 Great Britain separate control means controlling the upper portion are 344 403 9/1904 F hydraulic means and the upper portion is mounted on rollers contacting the lower portion. 10 ROBERT R. MACKEY, Primary Examiner. 

